Tuning device



sept. 19, 1939. A BLMN 2,173,"226

TUNING DEVICEy Filed April 27, 1937 Cttorneg such as a gang condenser, wherein the tuning ele- Patented Sept. 19, 1939' UNITED STATES TUNING DEVICE Aubert am, Philadelphia, n., minor a auna Corporation of America, a corporation of Dela- Application April 27, 1937, Serial No. 139,198

'I Claims.

This invention relates to improvements in tuning devices for radio receivers.

The principal object of the invention is to provide a tuning device embodying a tuning element,

ment is thoroughly shock-insulated from the chassis and from the driving mechanism whereby such tremors as are incident to the operation of the driving mechanism are prevented Afrom aifecting the tuning element and its associated mental movements of the gang condenser or other tuning element is ensured.

Still another object of the invention is to provide an extremely simple, compact, trouble-free, shock-proof tuning mechanism which lends itself readily to mass production methods.

Other objects and advantages will be apparent and the .invention itself will be best understood by reference to the followingA specification and to the accompanying drawing, wherein:

Figure 1 is avvertlcal sectional view of a tuning mechanism constructed and operated in accordance 'with the invention, and

Figure 2 is a detailed front elevational view taken on the line 2-2 oi' Fig. 1.

In the drawing, i designates the iront panel and 3 a base or shelf of the chassis of a radio receiver. Mounted above base 3 and supported as 'on shock-insulating rubber grommets l, is a variable condenser, indicated diagrammatically at C by the usual symbols. Condenser C may comprise a main tuning shaft Zi, a front plate 9 in which shaft 1 is journaled, and a number of frame members lI which, in addition to supporting the stator plates (not shown), lend rigidity to the device. The main tuning shaft 1, which is preferably rotatable through la given range of 180 extends forwardly beyond the iront plate 9 and has a hub I3 fixed thereon adjacent its outer end as by screw I5. y

Hub I3 has an indicating device i1 secured thereto in a 'plane normal to the axis of rotation of the tuning shaft. Indicator I1 may, as shown, comprise a dial the indicia of which may be read by reference to a fixed pointer I9 which is supported on a bracket 2l secured to the front panel I of the chassis. Preferably pointer I9 is bent outwardly from bracket 2| to form a chan'nel 23 within which the periphery of dial I1 is guided.

Channel 23 further serves to maintain the dial against 'such displacement as may occur due to warping or curling ofthe light weight material ofl which it may be, constituted.

Instead of a ldial, hub I3 may carry a pointer, in which case the scale bearing surface with which -the pointer is associated may be mounted in any suitable manner, as on bracket 2| or upon 'the front panel of the cabinet (not shown).

The extension of shaft 1, to which the hub I3 bearing the indicator I1 is afllxed, extends through, without touching, a stationary, coaxial, cylindrical member 25 which is supported on a bracket 21 secured to the front panel I of the chassis. The clearance between shaft 1 and cylinder 25 is preferably sufficient to permit of ra limited range of displacement or misalignment between these members. Member 25 serves as an axle for a sleeve 29 which is rotatably mounted on its outer surface.

A vibration damping member, indicated generally at 3| in both Figs. 1 and 2, serves to connect sleeve 29 and hub i3 in torque transfer relation. Member 3i may -be constituted of an annulus 33 formed of soi't rubber or the like and supported between two metal spiders 35, I5, which are fixed, respectively, on sleeve` 29 and hub I3. Each spider may comprise a plurality of spaced arms 31, 41 which extend radially outward from a central hub 39, 49, respectively. The arms on spider 35 preferably do not. register with the arms 41 on spider 45, but are arranged to lle intermediate adjacent of the arms 41. Studs Il! secure the rubber annulus 33 to arms 3l', and studs 43 secure it to arms 31. with and studs so arranged, the only driving connemn Vbetween sleeve 29 and hub i3 is through the vibration damping rubber annulus 33.

Any suitable or convenient drive mechanism may be' employed for imparting movement to sleeve 29. Thus, as shown in Fig. Si, sleeve 2S Y may carry a gear` segment 5I which meshes withl a smaller gear 53, driven by a knob on a drive shaft 51 which is supported on bracket 2l. AlfJ ternatively, a driving mechanism including a disc afiixed tosleeve 29 and ball/drive therefor, similar to that shown in U. S. Patent 2,076,825 to Donald R. De Tar, may be employed. i

Other modifications will suggest themselves to those `skilled in the art. It is to be understood, thereforathat the invention is notte be limited except as required by the prior art and the spirit of the appended claims.

Whatv is claimed is:

1. A tuning-device comprising a rotatable tuning shaft, driving means concentric with said shaft and spaced radially therefrom, means for mounting an indicator on said shaft and a resilient coupling interposed between said driving 5 means and said mounting means.

2. A tuning device comprising a rotatable shaft, driving means comprising a sleeve surrounding and spaced from said shaft intermediate the ends thereof, means for mounting an indicator adjacent an end of said shaft, a resilient coupling interposed between said driving means and said mounting means, and means for actuating said driving means.

3. A tuning device comprising a rotatable shaft having a given range of movement, a hub fixed to said shaft and supporting a device for indicating the angular position of saidshaft, means intermediate the ends of said shaft and comprising a sleeve surrounding-said shaft and spaced therefrom for driving said hub and hence said shaft and indicating device, and vibration damping means interposed between said driving means and hub for transmitting torque therebetween. 4. A tuning device comprising a rotatable shaft having a given range of movement, a hub fixed to said shaft and supporting a device for indicating the angular position of said shaft, a fixed hollow member coaxial with said shaft and spaced therefrom a distance sufficient to permit of a limited range of displacement therebetween, a rotatable sleeve on said member, a vibration damping element connected in torque transfer relation between said sleeve and said hub, and means for rotating said sleeve.

5. The combination with radio apparatus having a chassis base, of a tuning element having a rotatable shaft, vibration damping support on said base and upon which said tuning element is mounted, a driving element supported on said 5 base out of contact with said shaft, a driven 4element secured to said shaft, and a vibration damping coupling member connected between said driving and driven` elements.

6. In combination, a tuning element compris- 10 ing a rotatable shaft having a given range of movement, a vibration damping support upon which said tuning element is mounted, a hub fixed to said shaft and supporting a device for indicating the angular position of said shaft, a 15 stationary hollow member coaxial with said shaft and spaced therefrom, a rotatable sleeve on said hollow member, a vibration -damping member connected in torque transfer relation between said sleeve and hub, and means for rotating said 20 sleeve.

7. A tuning device comprising a tuning shaft having an indicator mounted adjacent an end section thereof, driving means for said shaft comprising a surrounding sleeve mounted for 25 independent movement out of contact with said shaft intermediate the ends thereof, a resilient coupling interposed between said sleeve and that end section of the shaft upon which the indicator is mounted, and means for moving said 30 sleeve.

ALBERT BLAIN. 

